Recorded data from macaque V1 and model details.

A) During laser stimulation, facilitated neurons had a fast onset response followed by a transient to sustained response profile similar to that seen following visual stimulus presentation. Immediately following laser offset, facilitated neurons in macaque V1 were quickly suppressed beyond their baseline firing rate for >100ms (left). The temporal response profile of suppressed neurons (right) reached peak suppression at ~100 ms after stimulation. After laser offset, the modeled and recorded neurons remained suppressed for ~200 ms and slowly returned to baseline. B) The modeled network is a recurrent neural network of 1000 excitatory and 250 inhibitory neurons and contains excitatory-excitatory, excitatory-inhibitory, inhibitory-excitatory, and inhibitory-inhibitory connections. Of the excitatory neurons, 200 contained the modeled opsin. C) The opsin conductance was modeled using a 3-state model, which includes an open, desensitized, and closed state. Increasing the number of photons (simulating different light levels) opens conductance channels (transient state) after which they become desensitized (sustained stated). When the light is turned off, conductance channels move to a closed state and the conductance decays to zero (left). A single simulated neuron and opsin conductance (right). As the opsin conductance increases, it drives the cell to fire at higher rates.